Feed-control means for turning machines



Nov. 4, 1930. c. L.. MATTlsoN 1,780,203

FEED CONTROL MEANS FOR TURNING MACHINESl Filed July 5, 1928 Nov.v4,1930. c. MA'rTlsoN FEED CONTROL MEANS FOR TURNING MACHINES Filed July 5,1928 i 2 Sheets-Sheet 2 Patented Nov. 4., 1930 l UNITEDN STATES CARL L.MATTISON, or RooxroRn, ILLINoIsi.v 'A' PATENTAOFFICE y' WORKS, OFRooxFoRn ILLINOIS, CORPORATION OI" ILLIi'IoIsv FEED-CONTROL MEANS FORTURNING MACHINES n l Application nea July 5,

remove material from the periphery thereof.

Vith such a machine the work is 4fed toward the rapidly rotating cutteruntil the cutter has reached therdesired depth of cut, this depth beingordinarily determined by suitable stop means interposedbetween thecutter and work supporting frames. ,This-pare ticular movement of thecutter and the work piece relative to each otherwill hereinafter' betermed feeding the'cutter` to depth.. VAfter the cutter has reached itsdepth, the rota- Y tion of the work piece throughasingle revolution,causes the cutter to remove stock from the periphery of the piece downto this particular dept n The feeding of thework to the cutter and in todepth is normallygoverned manually by the operator and in ca se the'workis fed too rapidly to depth, many undesirable ren sults may occur. Insome instances the work piece is thrown from between the two workcenters which of course endangers the oper# ator aswell as the machine.In other cases, too rapid feeding ofthe Work results intear-` ing thework, breaking of the cutter head-or cutter knives or in excessivedulling ofthe knives. i f

This is particularly true when work is beving turned from rough piecesof stock, asyfor example, from quarter-round stock of the type used forthe production ofbowling pins. For this purpose itis the'practi'ce touse work pieces'formed by quartering an unstripped hard maple log and itwill beapparent that when such a blank is centered between" the spindlesthere willbe corners which project beyond the body of the piece. Thefeed to Y depth may occur between two of these projecting corners and asa result the sudden contact of the knives with an exceedingly heavy cutmay cause breaking of the knives, and tearing or splitting of the stock.In

132s. yserial No. 290,474. f

ssIGNoR LTO `iszm'irrIsoNy MACHINE cautious after experiencing suchdifficulties and hence wastes a considerable amount of work-ing time by'feeding the cutter to depth too slowly. f

One object of the present invention is to provide a turning machineembodying means of a novel character operableto oontrolthe feedingof thework to depth so that an initial or roughing cutof stock may be removedfrom the periphery of a lrotatingwork piece andafter such an initialcutrhas been made to control the feedingof the work to a second depth ofcutso that a second layer of substantially uniformthickness may beremoved from the Vwork piece to produce an accurately turned piece ofWork. This makes possible cutting of the maximum amount of'stock which`mayvi-be safely removed atall times during the turning operationwithout undue danger to the-operator or to the machine.

It' hasalso been [found that, due primarily to the `fact that the Acutis made "on the side opposite from the operator, it is impossible forthe operator nto determine accurately ,whenl the cutting operation iscompleted and the work piece is often held in its operative positionadjacent thecutter for considerable time after the completionbfthecutting op,- 1

erationw During this time the `finished work piece continues torotate-and the cuttin edges `ofthe cutter knives rub against the surfacethereof which resultsfin burning the Work piece and heating the knivessoas to remove the temper therefrom., y y, Another object is to provide aturning Inachine embodying means operable to institute the,withdrawalvmoveinent ofthe Work table land" positively move the workout of contact with;` the cutteriupon the completion ofthe cuttingoperation `so .las to` determine definitely the time necessary forcompletion of the turning operation and to I revent injury to the knivesand to the wort piece due to continuedcontact of the two after completi-onof the `cutting operation.

Another object is to provide a turning Inacbine of thischaracterhavingmeans operable to signalthe operator; upon the `complef tionl of thecutting operation so thathe may nished 50 such cases the operator oftenbecomes unduly without loss of time move the work supporting frameto itsinoperative position and remove the finished work piece and position anew piece of work thereon.

Other objects and advantages will become apparent from the followingdescription taken in connection with the accompanying drawings in whichFigure 1 is a fragmentary front elevational view partiallyin section ofa wood turning machine embodying the preferred vform of the invention.

Fig. 2 is an endv elevational view of the machine shown in Fig. 1.

Fig. 3 is an enlarged portionof the machine shown in Fig. 2.

Fig. 4 is a diagrammatic view illustrating the limits of the roughingand finishing cuts taken from a piece of stock in the operation of thepreferred form of machine shown in Figs. 1 to 3. Y s

`While the invention is susceptible of various modifications andalternative constructions, I have shown in the drawings and will hereindescribe in detail the preferred embodiment, but it is to beunderstoodthat I do not thereby intendto limit the invention to the specific formdisclosed but intend to cover all modifications and alternativeconstructions falling within the spirit. and scope of the invention asexpressed in the appended claim.

The machine chosen for purposes of illustrationis of the type whichembodies a stationarily mounted rotating cutter head and the cutter.

a-swingable work table movable to` and from operativerelation with thecutter. A main frame or base 7 is provided on which a cutter spindle 8is rotatably mounted and carries a cutter 9 shown in dotted outline inthe drawings. VThe work is supported upon a movable table 10 mounted formovement between an operative positiony adjacent the cutterr 9 to aninoperative position remote from The table 10 is carried on the upperend of an upright frame 11 having its lower endpivotally supported bysuitable bearings 12 (Fig. 2) on the forward side of the base 7.

For swinging the table 10 toward and away from the frame 7 tomovethe'work to and from the cutter a rock shaft 15, supported at asubstantial distance from the frame 7 upon forwardly extending brackets16 secured to the frame 7, has a pair of lever arms 17 se- I curedthereto which are pivotally connected to the upper end of the frame 11by means of a pair of links 18. At one end of the shaft 15 an operativearm or lever 20 is secured whereby the shaft 15 may be rocked and thetable 10 moved toward and away from the cutter 9.

" "Upon the table 10 are supported a head stock 21 and a tail stock 22adapted for adjustment in a well known manner. The head C stockcomprises a spindle 23 at the forward also mounted, meshing with theworm wheel A,

25, and secured to the upper end of an upright driving shaft 28 which'is connected to a source of power (not shown) by means of vasuitableruniversalcoupling 29 lso as to permit swinging movement of thetable 10.

The tail stock 22 comprises a spindle 30 carrying onits inner end a spurcenter 31. As herein shown the spindle 30 is mounted in the tail stockbearing by means of a sleeve 32 which is arranged to be reciprocated tomove the spur center 31 by means of a lever 33 which is geared by meansof a pinion 35 to a rack 34 formed on the sleeve 32.

In the present embodiment a shaft 37 is mounted on the table 10 parallelto the spindles inv spaced bearings 38 and 42 and is rgearedto thespindles 23 and 30 by similar gear trains 39. 40, 41 and 45, 46, 47 sothat the two spindles will rotate in synchronism.

The gear 45 is splined to the shaft 37 so as a,

fed to depth, means is provided which is preferably operated in timedrelation to the work driving means to govern the'initial feed to'depthso as to remove an initial or roughing cut of material from theperiphery of the stock and thereafter to govern a second feeding todepth so as to remove a second layer of material which will of course beof a more uniform thickness due to the initial or roughing operationpreviously performed.

Thus'in the present embodiment of the invention a bracket 50 is mountedon the table 10 adjacent the tailstock end thereof and a cam member inthe form of a disk 52 is rotatably mounted thereon by means of a stud 53secured in the bracket. The cam member 52 is arranged to engage at itsedge with a roller 54 adjustably supported on the main frame 7 by anL-shaped bracket 55 so as to definitely limit the movement of the table10 toward the cutter 9.

The cam member 52 is preferably arranged for rotation in timed relationto work supporting spindles 23 and 30 through the me dium of Va pinion56 fixed on the'shaft 37 and engaging av gear 57 rotatably mounted onthe stud 53, the cam member being secured to the gear 57 by headedscrews 58. Thus it will be apparent that since the engagement of the cammember 52 with the roller 54 definitely limits the travel of the workpiece toward the cutter during the feeding of the cutter to depth, theshape of the cam member may be varied to produce any desired combinationof feeding in. movements of the work.

f The present embodiment of the invention IUS fijogo contemplates thecompletion of the turning operation by making two successive cuts aboutthe periphery of the work blank. To this end a dwell portion 59 isformed on the cam member 52 concentric with the axis of rotation of thecam member and when the turning operation is started it is contemplatedthatone end of this surface (the upper end as shown in the drawings)will be positioned so as to be engageable with the cam roller 54. Y

The work is positioned between the work spindles while they are ininoperativeV position remote from the cutter and the operator then pullsthe handle 2O to move the table toward the cutter 9 to feed the cutterto depth in the work piece, this depth being determined by Contact ofthe dwell surface 59 with the roller 54.v During such movement, therotation of the work spindles may be initiated by any preferred manualor automatic means (not shown) and after the roller 54 has engaged thedwell surface 59, the work is rotated once so that a roughiiig cut ofmaterial will be removed from the periphery of the blank by the cutter9.

The geared connection between the shaft 37 and the work spindles isproportioned so that the dwell surface 59 will remain in contact withthe roller '54 until the work has been rotated sufficiently to completethe imtial or roughing cut and an inwardlysloping cam surface 6l isprovided on the cam member 52 arranged to engage the roller 54 after thecompletion. of the roughing cut to permit the feeding of the cutter to asecond depth in the work piece. To cause such a second feeding of thecutter to depth, the operator continues to apply pressure to the handle2O to move the table 10 toward the .cutter andthe depth to which it isfed into the work piece is determined by engagement of the roller 54Cwith a. dwell surface 60 on the cam member 52 continuing from the innerend of the cam surface 6l. v

The rotation of the work continues during and after the second feedingof the cutter to depth and the dwell surface 60 `is of sufficient extentso that the work piece is'given one complete revolution while the tableis held stationary and a second or finishing cut is removed from theperiphery of the work iece.

It will be noted that the second or finishing cut is of substantiallyuniform depthentirely around the periphery of the work piece due to theprevious removal of the initial roughing cut. This is best illustratedin Fig. 4 which shows diagrammatically a work piece N of the type usedin producing bowling pins. The work piece which is formed by ouarteringa maple log, has projecting corners G9 and is centered at 70. At thecompletion of the first feeding to depth, the work piece is movedthrough one complete revolution and the cutter removes `material fromperiphery of the workpiece downto the dotted circle 71. After thecompletion of the initial cut down the dotted circle 71, the cutter isagainfed 'to the second depthand'asthe work piece is turned throughanother complete revolution the cutter removes the stock down yto `theline indicated by the dotted circle 7 9. thus producing a finished workpiece.

\ lnorder to prevent loss of working time, excessive drilling of theknives and burning of the work due to keeping the work contact with thecutter after completion of the cutting operation, a caniV surfaceGQ isformed on tl'ievcam member 52 leading outwardlyfrom the dwell surfaceand connecting to the dwell surface 59. IThe dwell surfacevO isV ofsufficient length so-that the work piece may be moved-through acompleteirevolution after` tliesecond feeding ofthe cutter `to depthand-aftervthe completionof the finserves to signal the operatorV so thathe may.`

fully retract Vthe table and without loss of time remove thefinishedwork piece and position a new spindles. y Y

From the foregoing it will be apparent that piece of work between thewhich maybe used for high speed production work without undue danger. tothe operator or to the machine since autom aticallyoper able means isprovided to so limit the initial feeding of the cutter to depth that itcannot take a heavy cut into a rough work piece such as would ordinarilytear the stock or break the cutter knives.

Furthermore, the provision of means to limit the .amount of stock takenoff during a number of successive cutting operations about the peripheryof the work piece makes possible the taking ofi' of the maximum safeamount of stock during each revolution of the work and makes theefficiency and the safety of the operation practically independent ofthe skill of the operator. Thus a more unskilled class of help may beused so as to reduce the cost of the finished work. The provision ofmeans to secure the above mentioned mode of operation also serves todetermine definitely the time required for the completion of a turningoperation and results in a higher rate of production.

It will also be apparent that since the control means is operable tolimit the initial feeding` of the cutter to depth, this feedingoperation may be accomplished more quickly than the invention providesVa turning machine heretofore and still With utmost safety,- With aconsequent saving of operating time.

The provision of. means torsignal the operay tor When the cuttingoperation is completed alsopr'events loss of operating time and resultsin'greater production. rlhe signalling means automatically institutesthe With- Y dra-Wal movement Vof the Work from the cutter and alsoprevents the production of burned Work pieces and undue dulling of thecutter knives with a resultant saving of expense.

I claim as my invention:

A lathe comprising a cutter and a Work support one mounted so as to bemovable With respect to the other through a substantial range, manualmeans vfor imparting said movement, a combinedcam and pattern device, anabutment engaged thereby to govern a certain inner portion of saidrange, said cam device comprising a succession of pattern contours inradially stepped relation to each other7 the engagement of which Withsaid abutment determines the pattern of the crosssection of the Workthen being cut, While the steps or pronounced portions of the camprovide comparatively'abrupt shifts of distance between the Work andcutter, the angular pattern dimension of the cam of greater radius beingsuiiciently prolonged to control the complete cross-section of the Workthen being cut and so that When its engagement With the abutment isrepeated its advance portion having spaced the cutter and Work theyremain spaced long enough to aiord the operator full opportunity tomanually complete the range of Withdrawal movement.

In testimony whereof, I have hereunto affixed my signature.

v CARL L. MATTISON.

